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They’re not chasing birds or deer. They’re chasing scent.
The aroma of animal scat, in fact.
They are Conservation Canines, a high-energy, ball-obsessed detector dog group being increasingly recruited to aid in wildlife conservation. Samples of wildlife scat provide experts with a multitude of information — without having to trap and take samples from wildlife.
These special dogs, many rescued from shelters, undergo intensive training to become doggie detectives with the Center for Conservation Biology at the University of Washington. The dogs are trained and motivated to accurately locate the appropriate scent. “Our dogs are quick to learn the game,” said wildlife biologist Suzie Marlow, who joined Conservation Canines in 2012. Marlow, who began as an orienteer and scat volunteer, said their dogs think of finding wildlife scat as a game.
“Simply put: find the target odor equals play ball,” she said.
Recently, this “target odor” was mink scat. Experts wanted to determine how the polychlorinated biphenyl (PCB) contamination in New York’s Hudson River affected populations of wildlife, particularly mink, along the river. They brought in the Conservation Canines to sniff out the answer.
Mink live along rivers, diving for fish and eating frogs, birds, mice and other wildlife. As mink eat wildlife carrying PCBs, the persistent, toxic chemical builds up in their bodies. Laboratory studies have documented that mink are sensitive to PCB exposure and can experience reproductive impairment and mortality. The dogs of Conservation Canines were needed to see if those laboratory effects might be reflected in the mink populations of the Hudson River.
Conservation Canines sniffed out thousands of mink scat samples over a two year period. After reviewing the data, experts found that the mink population was drastically (approximately 40%) lower in the Hudson River when compared to the Mohawk River, a Hudson tributary without high levels of PCB contamination. The dangers to mink are documented in a new peer-reviewed, multi-year study commissioned by the Hudson River Natural Resource Trustees.
General Electric discharged PCBs into the Hudson River from two plants in Hudson Falls and Fort Edward, NY. The Trustees are studying injuries caused by these PCBs. To date, the Trustees have documented injuries to groundwater, surface water, recreational fishing and navigation and are evaluating injury to other resources and habitats.
Mink scat is just one of the scents these canines can detect. Their dogs can locate species that were thought to be extinct, an invasive seed even before the plant breaks through the surface, and pollutants in old, urban structures. “Single surveys provide information on species’ interactions and entire ecosystems over vast spaces and if repeated, can assess interactions over time,” Marlow said.
In 2016, Conservation Canines set out to prove that their dogs could detect one of the lowest of odor profiles. Marlow and her detector dog Ranger traveled to Connecticut to assist Tracy Rittenhouse, a University of Connecticut professor of natural resources and the environment. Rittenhouse was on the lookout for Eastern cottontail and New England cottontail nests.
“I was committed to trying to get the Conservation Canines organization out here to the East coast,” Rittenhouse said. “Finding the cottontail nest is an extremely difficult thing to do, so I wanted to go to who I viewed as the best organization at training dogs.”
The New England cottontail is the only rabbit native to New England and east of the Hudson River in New York. Eastern cottontails were introduced to the region decades ago, replacing New England cottontails in many areas. Cottontails can be difficult to follow because of their protective camouflage and thick habitat.
Ranger, who was systematically introduced to the scent of multiple nests that week, put his head down low, stuck his nose out, and eagerly went to work, Marlow said.
Rittenhouse, who accompanied Marlow and Ranger on their rabbit expedition, said that the cottontails poked their fuzzy, little heads out of the nest and started hopping away a little bit, “but Ranger pointed to each one individually with his nose and then looked to the trainer and got his ball reward.”
The Conservation Canines provided key data to the ongoing initiative to restore the New England cottontail. As a result of advanced research and conservation, the cottontail was removed as a candidate for Endangered Species Act protection in 2015, but the U.S. Fish and Wildlife Service stressed the need for continuing efforts.
“I think it’s impressive the efforts that have gone into the New England cottontail,” Rittenhouse said. “A lot of groups can train their dogs to find scat or things that are smelly, but Conservation Canines has many successes at training dogs on things that have very little odor, and it’s really impressive.”
The U.S. Fish and Wildlife Service “has been super successful at funding habitat management and creating enough habitat for species so that they are not on the Endangered Species list,” she added.
To learn about what other projects canines are sniffing out, check out their K9 Odor Detection page. You can learn more about the mink study by checking out the Hudson River Natural Resource Trustees fact sheet and press release, and the peer-reviewed Scientific Reports publication, titled ‘Large-scale variation in density of an aquatic ecosystem indicator species’.